Adjuvant Treatment Decisions among Older Women with Early-Stage Breast Cancer Seen in Multidisciplinary Consultation vs. Standard Consultation

Abstract

<h3>Purpose/Objective(s)</h3> Randomized studies and national guidelines support de-escalation of adjuvant therapy for a target population of woman ≥65 years with Stage I, ER positive breast cancer after breast conserving surgery. We sought to evaluate the impact of a multidisciplinary clinic (MDC) in this population by comparing treatment patterns and patient perceptions of adjuvant radiation therapy (RT) and hormone therapy (HT) between patients seen in MDC vs. standard consultation. <h3>Materials/Methods</h3> Medical records were retrospectively reviewed for women in the above target population who underwent surgery between 8/2020-11/2021 at our institution. Two cohorts were included: (1) patients seen in MDC, and 2) patients seen in standard clinic separately by medical and radiation oncology (non-MDC cohort). The non-MDC patients either declined MDC, could not attend an MDC clinic day, and/or were not referred to the MDC. Patients in the MDC cohort were also prospectively administered validated questionnaires to evaluate patient treatment preferences including the Decision Autonomy Preference Scale (DAPS) and Medical Maximizing-Minimizing Scale (MMS). Chi square, t-tests, and non-parametric equivalents compared demographics and logistic and linear regression evaluated RT and HT use and survey score outcomes between cohorts. <h3>Results</h3> A total of 90 patients met inclusion criteria, with 23 MDC and 67 non-MDC patients. There was no difference between the cohorts in age, Oncotype Recurrence Score, margin status, or tumor histology, grade, or focality. For the MDC cohort, there were significantly fewer sentinel lymph node biopsies performed (44% vs. 74%, p=0.006), and tumor size was smaller (0.6 vs. 1.1 cm, p<0.005), although all tumors were pT1c or less. Significantly fewer MDC patients received RT (61% vs. 82%, OR=0.34, p=0.046). The MDC cohort was more likely to undergo accelerated (vs. standard hypofractionated) RT (57% vs. 27%, OR 3.61, p=0.039). There was no difference in use of HT between cohorts (75% vs 76%, OR 1.08, p=0.885). Among the MDC cohort, all who preferred decisions be made "mostly by the patient" on the DAPS elected RT. Increasing MMS total score was associated with higher odds of RT (OR 1.43, p=0.027), with no "minimizers" (score <40) electing RT. <h3>Conclusion</h3> For women ≥65 years with early stage, ER positive breast cancer, MDC participation was associated with lower use of adjuvant RT and selection of shorter RT regimens versus standard consultation. These results support the role of the MDC in facilitating shared decision-making, perhaps enhancing patient comfort with forgoing more aggressive therapies. Responses from the DAPS and MMS tools indicate that patient treatment preference may be predictable, highlighting an opportunity to better tailor consultation discussions and recommendations based on intrinsic patient preferences and individual goals.